Update(2019-08-19): [BigInt][1] is now part of Firefox and Chrome; you no longer need a library:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    const bigInt1 = 1111111111111111111111111111111n;
    const bigInt2 = BigInt(&quot;1111111111111111111111111111111&quot;)
    console.log((bigInt1 + bigInt2)+&quot;&quot;)

&lt;!-- end snippet --&gt;

Original answer:

If you need arbitrary-precision decimal numbers, use [Javascript-bignum][2], as it is correct and fast.

  [1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#Description
  [2]: https://github.com/jtobey/javascript-bignum

[Big Number][1].


  [1]: http://jsfromhell.com/classes/bignumber

    import urllib2

    website = &quot;WEBSITE&quot;
    openwebsite = urllib2.urlopen(website)
    html = getwebsite.read()
    
    print html

So far so good. 

But I want only href links from the plain text HTML. How can I solve this problem? 


How can I get href links from HTML using Python?

So, I have a class with a constructor like this:

    public FilterList(Set&lt;Integer&gt; labels) {
        ...
    }

and I want to construct a new `FilterList` object with an empty set. Following Joshua Bloch&#39;s advice in his book Effective Java, I don&#39;t want to create a new object for the empty set; I&#39;ll just use `Collections.emptySet()` instead:

    FilterList emptyList = new FilterList(Collections.emptySet());

This gives me an error, complaining that `java.util.Set&lt;java.lang.Object&gt;` is not a `java.util.Set&lt;java.lang.Integer&gt;`. OK, how about this:

    FilterList emptyList = new FilterList((Set&lt;Integer&gt;)Collections.emptySet());

This also gives me an error! Ok, how about this:

    Set&lt;Integer&gt; empty = Collections.emptySet();
    FilterList emptyList = new FilterList(empty);

Hey, it works! But why? After all, Java doesn&#39;t have type inference, which is why you get an unchecked conversion warning if you do `Set&lt;Integer&gt; foo = new TreeSet()` instead of `Set&lt;Integer&gt; foo = new TreeSet&lt;Integer&gt;()`. But `Set&lt;Integer&gt; empty = Collections.emptySet();` works without even a warning. Why is that?

Why does using Collections.emptySet() with generics work in assignment but not as a method parameter?

Is there a bignum built into JavaScript or browsers?

The alternate is loading an external library like

    &lt;script type=&quot;text/javascript&quot; src=&quot;the_bignum_library.js&quot;&gt;&lt;/script&gt;

but that seems slow and may trigger a security warning.

I&#39;ve considered basing my own off of http://github.com/silentmatt/javascript-biginteger or http://www.mainebrook.com/john/fun/euler.html. Alternately, is the solution to call into a  Java bignum library such as apfloat?




What is the standard solution in JavaScript for handling big numbers (BigNum)?

Is there a bignum built into JavaScript or browsers?
The alternate is loading an external library like
<pre><code class="hljs language-php-template">&#x3C;script type="text/javascript" src="the_bignum_library.js">&#x3C;/script>
</code></pre>
but that seems slow and may trigger a security warning.
I've considered basing my own off of <a href="http://github.com/silentmatt/javascript-biginteger" target="_blank" rel="noopener noreferrer">http://github.com/silentmatt/javascript-biginteger</a> or <a href="http://www.mainebrook.com/john/fun/euler.html" target="_blank" rel="noopener noreferrer">http://www.mainebrook.com/john/fun/euler.html</a>. Alternately, is the solution to call into a Java bignum library such as apfloat?

Quick question: I need to allow an input to only accept letters, from a to z and from A to Z, but can&#39;t find any expression for that. I want to use the javascript test() method.

javascript regex : only english letters allowed

Does anyone know how I can take a MySQL `datetime` data type value, such as `YYYY-MM-DD HH:MM:SS` and either parse it or convert it to work in JavaScript&#39;s `Date()` function, for example:- Date(&#39;YYYY, MM, DD, HH, MM, SS);

Thank you!

Convert MySql DateTime stamp into JavaScript&#39;s Date format

The same origin policy
----------------------
I wanted to make a community wiki regarding HTML/JS **same-origin policies** to hopefully help anyone searching for this topic. This is one of the most searched-for topics on SO and there is no consolidated wiki for it so here I go :)


&gt; The same origin policy prevents a
&gt; document or script loaded from one
&gt; origin from getting or setting
&gt; properties of a document from another
&gt; origin. This policy dates all the way
&gt; back to Netscape Navigator 2.0.

What are some of your favorite ways to go around same-origin policies?
----------------------------------------
Please keep examples verbose and preferably also link your sources.

  [1]: http://www.w3.org/TR/access-control/
  [2]: http://hacks.mozilla.org/2009/07/cross-site-xmlhttprequest-with-cors/

Ways to circumvent the same-origin policy

Using javascript with or without Jquery, I need to a create a gradient of colours based on a start and finish color. Is this possible to do programmatically?

The end colour is only ever going to be darker shade of the start colour and it&#39;s for an unordered list which I have no control over the number of li items. I&#39;m looking for a solution that allows me to pick a start and end color, convert the hex value into RGB so it can be manipulated in code. The starting RGB values gets incremented by a step value calculated based upon the number of items.

so if the list had 8 items then the it needs to increment the seperate Red Green Blue values in 8 steps to achieve the final colour. Is there a better way to do it and if so where can I find some sample code? 


Javascript color gradient

I just came across [this piece][1] in the Mozilla Javascript documentation:

    var len = this.length &gt;&gt;&gt; 0;  

I don&#39;t quite understand why this is being done. What good does zero-fill right shifting `this.length` by `0` do? As far as I understand, it does exactly nothing. Is it to safely establish a default value for `len`, even if `this.length` is not an integer? Can this ever feasibly be the case? If so, what&#39;s the difference between `&gt;&gt; 0` and `&gt;&gt;&gt; 0`?


  [1]: https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Objects/Array/IndexOf

What good does zero-fill bit-shifting by 0 do? (a &gt;&gt;&gt; 0)

    $a = &#39;35&#39;;
    $b = &#39;-34.99&#39;;
    echo ($a + $b);

Results in 0.009999999999998

What is up with that? I wondered why my program kept reporting odd results.

Why doesn&#39;t PHP return the expected 0.01?

PHP - Floating Number Precision

I encountered negative zero in output from python; it&#39;s created for example as follows:

    k = 0.0
    print(-k)

The output will be `-0.0`.

However, when I compare the `-k` to 0.0 for equality, it yields True. Is there any difference between `0.0` and `-0.0` (I don&#39;t care that they presumably have different internal representation; I only care about their behavior in a program.) Is there any hidden traps I should be aware of?

negative zero in python

I am trying to truncate decimal numbers to decimal places. Something like this:
 
    5.467   -&gt; 5.46  
    985.943 -&gt; 985.94

`toFixed(2)` does just  about the right thing but it rounds off the value. I don&#39;t need the value rounded off. Hope this is possible in javascript.

Truncate (not round off) decimal numbers in javascript

    assert(0.1 + 0.2 != 0.3); // shall be true

is my favorite check that a language uses native floating point arithmetic.

## C++ ##

    #include &lt;cstdio&gt;
     
    int main()
    {
       printf(&quot;%d\n&quot;, (0.1 + 0.2 != 0.3));
       return 0;
    }

Output:

    1
http://ideone.com/ErBMd

## Python ##

    print(0.1 + 0.2 != 0.3)

Output:

    True

http://ideone.com/TuKsd

## Other examples ##

 - Java: http://ideone.com/EPO6X
 - C#: http://ideone.com/s14tV

Why is this not true for D? As understand D uses native floating point numbers. Is this a bug? Do they use some specific number representation? Something else? Pretty confusing.

## D ##

    import std.stdio;
     
    void main()
    {
       writeln(0.1 + 0.2 != 0.3);
    }

Output:

    false

http://ideone.com/mX6zF

---
## UPDATE ##
Thanks to [LukeH][1]. This is an effect of Floating Point Constant Folding described [there][2]. 

Code:

    import std.stdio;
     
    void main()
    {
       writeln(0.1 + 0.2 != 0.3); // constant folding is done in real precision
     
       auto a = 0.1;
       auto b = 0.2;
       writeln(a + b != 0.3);     // standard calculation in double precision
    }

Output:

    false
    true

http://ideone.com/z6ZLk


  [1]: https://stackoverflow.com/users/55847/lukeh
  [2]: http://www.d-programming-language.org/float.html





Why 0.1 + 0.2 == 0.3 in D?

The following code is obviously wrong.  What&#39;s the problem?

    i &lt;- 0.1
    i &lt;- i + 0.05
    i
    ## [1] 0.15
    if(i==0.15) cat(&quot;i equals 0.15&quot;) else cat(&quot;i does not equal 0.15&quot;)
    ## i does not equal 0.15

Why are these numbers not equal?

In Haskell, what is the difference between an `Int` and an `Integer`? Where is the answer documented?

Content Type	Original Author	Original Content on Stackoverflow
Question	David Cary	View Question on Stackoverflow
Solution 1 - Javascript	jnnnnn	View Answer on Stackoverflow
Solution 2 - Javascript	Babiker	View Answer on Stackoverflow

What is the standard solution in JavaScript for handling big numbers (BigNum)?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Why does using Collections.emptySet() with generics work in assignment but not as a method parameter?

How can I get href links from HTML using Python?

Attributions